changelist should be able to iter on mounts

Modified changelist_gather()ing for the mountpoint property.
Now instead of iterating on all dataset descendants, we read
/proc/self/mounts and iterate on the mounted descendant datasets only.

Switched changelist implementation from a uu_list_* to uu_avl_* in
order to  reduce changlist code-path's worst case time complexity.

Reviewed by: Don Brady <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Alek Pinchuk <[email protected]>
Closes #7967 

3 files changed, 192 insertions, 2 deletions

diff --git a/tests/runfiles/linux.run b/tests/runfiles/linux.run
index 95e70f043..32bc9c328 100644
--- a/tests/runfiles/linux.run
+++ b/tests/runfiles/linux.run
@@ -277,7 +277,7 @@ tags = ['functional', 'cli_root', 'zfs_unload-key']
 tests = ['zfs_unmount_001_pos', 'zfs_unmount_002_pos', 'zfs_unmount_003_pos',
     'zfs_unmount_004_pos', 'zfs_unmount_005_pos', 'zfs_unmount_006_pos',
     'zfs_unmount_007_neg', 'zfs_unmount_008_neg', 'zfs_unmount_009_pos',
-    'zfs_unmount_all_001_pos']
+    'zfs_unmount_all_001_pos', 'zfs_unmount_nested']
 tags = ['functional', 'cli_root', 'zfs_unmount']
 
 [tests/functional/cli_root/zfs_unshare]
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/Makefile.am b/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/Makefile.am
index 9ea809f26..34cbb17ae 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/Makefile.am
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/Makefile.am
@@ -11,7 +11,8 @@ dist_pkgdata_SCRIPTS = \
 	zfs_unmount_007_neg.ksh \
 	zfs_unmount_008_neg.ksh \
 	zfs_unmount_009_pos.ksh \
-	zfs_unmount_all_001_pos.ksh
+	zfs_unmount_all_001_pos.ksh \
+	zfs_unmount_nested.ksh
 
 dist_pkgdata_DATA = \
 	zfs_unmount.cfg \
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/zfs_unmount_nested.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/zfs_unmount_nested.ksh
new file mode 100755
index 000000000..73eae6a25
--- /dev/null
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_unmount/zfs_unmount_nested.ksh
@@ -0,0 +1,189 @@
+#!/bin/ksh -p
+#
+# CDDL HEADER START
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy is of the CDDL is also available via the Internet
+# at http://www.illumos.org/license/CDDL.
+#
+# CDDL HEADER END
+#
+
+#
+# Copyright (c) 2018 Datto Inc.
+#
+
+. $STF_SUITE/include/libtest.shlib
+
+#
+# DESCRIPTION:
+#	zfs unmount should work on nested datasets
+#
+# STRATEGY:
+#	1. Create a set of nested datasets
+#	2. Unmount a nested dataset and make sure it is unmounted
+#	3. Ensure the dataset deeper than the one above is also unmounted
+#	4. Ensure the datasets shallower than the unmounted one is still mounted
+#	5. Repeat from step 2 with other mountpoint values and shallower nesting
+#
+
+verify_runnable "both"
+
+function nesting_cleanup
+{
+	log_must zfs destroy -fR $TESTPOOL/a
+	log_must zfs destroy -fR $TESTPOOL/b
+	log_must zfs destroy -fR $TESTPOOL/c
+	log_must zfs destroy -fR $TESTPOOL/d
+}
+
+log_onexit nesting_cleanup
+
+set -A test_depths 30 16 3
+
+dsA32=$(printf 'a/%.0s' {1..32})"a"
+log_must zfs create -p $TESTPOOL/$dsA32
+
+dsB32=$(printf 'b/%.0s' {1..32})"b"
+log_must zfs create -o mountpoint=none -p $TESTPOOL/$dsB32
+log_mustnot mount -t zfs $TESTPOOL/$dsB32 /mnt
+
+dsC32=$(printf 'c/%.0s' {1..32})"c"
+log_must zfs create -o mountpoint=legacy -p $TESTPOOL/$dsC32
+log_must mount -t zfs $TESTPOOL/$dsC32 /mnt
+
+dsD32=$(printf 'd/%.0s' {1..32})"d"
+log_must zfs create -o mountpoint=/$TESTPOOL/mnt -p $TESTPOOL/$dsD32
+
+
+for d in ${test_depths[@]}; do
+	# default mountpoint
+	ds_pre=$(printf 'a/%.0s' {1..$(($d-2))})"a"
+	ds=$(printf 'a/%.0s' {1..$(($d-1))})"a"
+	ds_post=$(printf 'a/%.0s' {1..$(($d))})"a"
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) not initially mounted"
+	fi
+
+	log_must zfs snapshot $TESTPOOL/$ds@snap
+	# force snapshot mount in .zfs
+	log_must ls /$TESTPOOL/$ds/.zfs/snapshot/snap
+	log_must zfs unmount $TESTPOOL/$ds
+
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$ds_pre is not mounted"
+	fi
+	if ismounted $TESTPOOL/$ds; then
+		log_fail "$ds is mounted"
+	fi
+	if ismounted $TESTPOOL/$ds_post; then
+		log_fail "$ds_post (post) is mounted"
+	fi
+
+
+	# mountpoint=none
+	ds_pre=$(printf 'b/%.0s' {1..$(($d-2))})"b"
+	ds=$(printf 'b/%.0s' {1..$(($d-1))})"b"
+	ds_post=$(printf 'b/%.0s' {1..$(($d))})"b"
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) not initially mounted"
+	fi
+
+	log_must zfs snapshot $TESTPOOL/$ds@snap
+	# force snapshot mount in .zfs
+	log_must ls /$TESTPOOL/$ds/.zfs/snapshot/snap
+	log_must zfs unmount $TESTPOOL/$ds
+
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not mounted"
+	fi
+	if ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds is mounted"
+	fi
+	if ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) is mounted"
+	fi
+
+
+	# mountpoint=legacy
+	ds_pre=$(printf 'c/%.0s' {1..$(($d-2))})"c"
+	ds=$(printf 'c/%.0s' {1..$(($d-1))})"c"
+	ds_post=$(printf 'c/%.0s' {1..$(($d))})"c"
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) not initially mounted"
+	fi
+
+	log_must zfs snapshot $TESTPOOL/$ds@snap
+	# force snapshot mount in .zfs
+	log_must ls /$TESTPOOL/$ds/.zfs/snapshot/snap
+	log_must zfs unmount $TESTPOOL/$ds
+
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not mounted"
+	fi
+	if ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds is mounted"
+	fi
+	if ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) is mounted"
+	fi
+
+
+	# mountpoint=testpool/mnt
+	ds_pre=$(printf 'd/%.0s' {1..$(($d-2))})"d"
+	ds=$(printf 'd/%.0s' {1..$(($d-1))})"d"
+	ds_post=$(printf 'd/%.0s' {1..$(($d))})"d"
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$TESTPOOL/$ds_pre (pre) not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds; then
+		log_fail "$TESTPOOL/$ds not initially mounted"
+	fi
+	if ! ismounted $TESTPOOL/$ds_post; then
+		log_fail "$TESTPOOL/$ds_post (post) not initially mounted"
+	fi
+
+	log_must zfs snapshot $TESTPOOL/$ds@snap
+	# force snapshot mount in .zfs
+	log_must ls /$TESTPOOL/$ds/.zfs/snapshot/snap
+	log_must zfs unmount $TESTPOOL/$ds
+
+	if ! ismounted $TESTPOOL/$ds_pre; then
+		log_fail "$ds_pre is not mounted"
+	fi
+	if ismounted $TESTPOOL/$ds; then
+		log_fail "$ds is mounted"
+	fi
+	if ismounted $TESTPOOL/$ds_post; then
+		log_fail "$ds_post (post) is mounted"
+	fi
+done
+
+log_must zpool export $TESTPOOL
+log_must rmdir /testpool/mnt # remove the mountpoint we created
+log_must zpool import $TESTPOOL
+
+log_pass "Verified nested dataset are unmounted."